Sayfoo

I hit my headers with my infrared temp gun right at the heads and there is a difference in temp. I'm sure that this is a product of differences in the intake--stock carb and manifold, '69 427/390--and the exhaust bends, coolant flow, etc., and I'm wondering what a normal spread would be. Measured after extended fast idle with normal water temp.
#1 cylinder=675 deg F 2=720
3=720 4=685
5=805 6=815
7=860 8=840
Look ok to you?

Sayfoo

No thoughts on normal temp spread???

MelWff

best guess is most people dont do this other than perhaps when an engine is being dynoed with headers.

v2racing

The 4 front cylinders are closer the to carbs primaries than the rear 4 and the temps seem to show the fuel distribution differences. Under a WOT pull, the individual cylinder temps would probably be very different than at idle.

With a stock carb and manifold, there is not much you can do about fuel distribution. If it's running good, just drive it and don't worry about it.

Mike

bashcraft

A Holley carb with 4 corner idle could take care of this, but the temps at idle don't mean a lot. As was said WOT temps will be different and that's what matters.

I have a Holley 950 HP with 4 corner idle on my 502.

myohpe@gmail.com

Exhaust temps you listed are all within 20% of each other. Normal mostly. What you look for measuring header pipes is a big difference, that shows problems. If you have 700-800 degrees on 6 or 7 pipes, but 1 or 2 pipes measures 200 or 1200, you got trouble. Checking spark plugs is the best way to diagnose how your individual cylinders are running. Plenty of info on the internet on plug coloring and tuning.

bazza77

Yeah looks OK , I remember with my tripower idling it didn't see as big of a difference but my gun could also register the spike when the exhaust valve opened .

Grumpy 427

The only time you would typically check those is to see if you had a dead hole.

derekderek

Okay, so the front cylinders idle mixture is better and the back cylinders idle mixture is somewhat lean and that's why they read hotter?

calwldlife

could have to do with the way water flows thru
block

front cyl get colder water thus changing
cyl temps.

i see no problem with your posted temps.